diff --git a/PROJECT-PLAN.md b/PROJECT-PLAN.md new file mode 100644 index 0000000..811591b --- /dev/null +++ b/PROJECT-PLAN.md @@ -0,0 +1,397 @@ +# CNC Router Project Plan — Research → Prototype → Production + +> **Repository:** git.paraskeva.net/nearxos/cnc-router +> **Last Updated:** 2026-06-22 +> **Status:** Research Phase (∼60% complete); Prototype Phase (∼5% complete) + +--- + +## 1. Executive Summary + +This project designs and builds a **rail-free, multi-belt/cable-driven suspended CNC router** for semi-professional woodworking and DIY sheet-goods fabrication. Unlike traditional gantry routers that require massive frames, expensive linear rails, and a dedicated workshop footprint, this machine uses a **surface-riding sled** controlled by 4 or 8 tensioned belts anchored to a lightweight perimeter frame, achieving a large work area (up to 4′×8′/1.2 m×2.4 m) from a highly portable and cost-effective package. + +**Why this matters:** Existing solutions force a painful trade-off: +- **Gordix / Maslow 4 / Cubiio X** are portable but either closed-source, mechanically limited (4-belt yaw problems), or extremely expensive per m². +- **Traditional gantry CNCs** offer rigidity and accuracy but require thousands of dollars in frame and rails, plus dedicated floor space. + +**Our approach:** Combine the best of both worlds — the portability and workspace flexibility of Gordix/Maslow with the open-source firmware, robust DC servo architecture, and community-validated kinematics of the Maslow 4 ecosystem. The design scales from a $261 1 m×1 m 3D-printable prototype (proof of concept, 4-belt) to a $737 4′×8′ production machine (8-belt Gordix-style with DC geared servos, aluminum sled, and Makita RT0701C). + +**Key design decisions:** +- **FluidNC firmware** (open-source ESP32 motion controller) for maximum configurability and custom kinematics +- **8-belt constraint-locked kinematics** for production build (eliminates yaw mathematically without software correction) +- **Custom ESP32-S3 PCB** (v1.0 designed) with 8× TMC2209 stepper drivers, dual UART buses, and Maslow4-compatible pinout +- **Two-phase build:** cheap 1 m×1 m prototype first, then full-scale production sled + +--- + +## 2. Current Status + +### 2.1 Completed Research & Design + +| Area | Status | Details | +|------|--------|---------| +| **Competitive Analysis** | ✅ Complete | README.md — Gordix, Maslow 4, Cubiio X, Maker Made M2 compared across 15 metrics (kinematics, cost, weight, software, calibration) | +| **Kinematics Simulation** | ✅ Complete | Python simulation of 8-belt Gordix geometry; forward & inverse kinematics validated; workspace heatmap generated (kinematics/, simulate_grid.py, tension_analysis.py) | +| **BOM & Cost Analysis** | ✅ Complete | Two-scale BOM in BOM-Evaluation.md: $261 prototype (1 m×1 m, NEMA 17, 4-belt), $737 production sled (4′×8′, DC servos, 8-belt, Makita router) | +| **PCB v1.0 Schematic** | ✅ Complete | Full netlist in pcb/schematic_netlist.md — ESP32-S3 + 8× TMC2209 + power regulation (24V/5V/3.3V), 4-layer stackup, UART bus topology | +| **FluidNC Machine Config** | ✅ Complete | esp32-s3-pinout.yml — complete machine configuration: dual-motor gantry axes, homing, limits, probe, UART addressing, TMC2209 parameters | +| **Software Pipeline** | ✅ Defined | CAD (Fusion 360/Onshape/Inkscape) → CAM (Kiri:Moto/Estlcam/G-code sender) → FluidNC custom kinematics | + +### 2.2 What's Designed but Not Yet Built + +| Item | Status | Notes | +|------|--------|-------| +| ESP32-S3 PCB layout (KiCad) | ⬜ Not started | Netlist complete; needs board layout, routing, ERC/DRC | +| Prototype 3D-printed parts | ⬜ Not started | Sled, corner anchors, GT2 spool holders — designed but not printed | +| FluidNC custom kinematics module | ⬜ Not started | The 4-belt/8-belt kinematic transform needs to be coded as a FluidNC custom kinematics module (C++ or via Maslow4 fork) | +| Enclosure / frame design | ⬜ Not started | Plywood perimeter frame for prototype; extrusion or ply for production | +| Dust collection system | ⬜ Not started | Active vacuum nozzle wrapping Makita router body — concept only | + +### 2.3 Repository Structure + +``` +cnc-router/ +├── README.md # Competitive analysis, design rationale, software strategy +├── BOM-Evaluation.md # Two-scale BOM with component tables and cost breakdown +├── PROJECT-PLAN.md # ← THIS FILE — roadmap and phased development plan +├── kinematics/ +│ ├── kinematics.py # 8-belt Gordix forward/inverse kinematics +│ ├── simulate_grid.py # Workspace grid simulation +│ ├── tension_analysis.py # Belt tension analysis +│ ├── workspace_heatmap.csv +│ └── workspace_heatmap.png +└── pcb/ + ├── esp32-s3-pinout.yml # FluidNC machine configuration + └── schematic_netlist.md # Full schematic netlist, BOM, and stackup +``` + +--- + +## 3. Development Phases + +### 3.1 Phase 1: Prototype (1 m × 1 m, 4-Belt) + +**Goal:** A low-cost, low-risk proof of concept to validate belt-driven suspended kinematics, firmware integration, and basic accuracy — before investing in the full-scale machine. + +**Target Budget:** ~$261 + +**Core Specs:** +- Work area: 1 m × 1 m (with GT2 timing belts, corner anchors) +- Kinematics: 4-belt suspended triangle (simpler, yaw managed in software) +- Motors: 4× NEMA 17 (59 N·cm, 1.8° step) +- Drivers: 4× TMC2209 (UART mode, stealthChop for quiet operation) +- Controller: ESP32 NodeMCU dev board + GRBL Arduino shield (or early FluidNC flash) +- Sled: 3D-printed PLA, dual-mount holes per corner (upgradable to 8-belt) +- Spindle: Bosch Colt / Makita clone (65 mm body, 500 W brushless DC option) +- Z-axis: Mini linear slide with T8 leadscrew + NEMA 17 +- Frame: Plywood perimeter + corner brackets + +**Phase 1 Deliverables:** + +| # | Task | Est. Effort | Dependencies | +|---|------|-------------|-------------| +| P1.1 | Order prototype parts per BOM-Evaluation.md | 1 day | None | +| P1.2 | 3D-print sled, corner anchors, GT2 spools | 3 days | P1.1 (ordered parts) | +| P1.3 | Build plywood frame (1 m × 1 m) | 1 day | P1.2 | +| P1.4 | Assemble electronics (ESP32 + TMC2209s) on breadboard/protoboard | 2 days | P1.1 | +| P1.5 | Flash FluidNC with 4-belt kinematics | 1 day | P1.4 | +| P1.6 | Initial belt tensioning and calibration | 1 day | P1.3, P1.5 | +| P1.7 | Test grid: cut 10 cm squares at 5 positions across workspace | 1 day | P1.6 | +| P1.8 | Measure accuracy; document deviation map | 1 day | P1.7 | +| P1.9 | Gate review — proceed to Phase 2? | — | P1.8 | + +**Success Criteria (Phase 1):** +- [ ] All 4 belts remain tensioned across full workspace without slipping +- [ ] Sled reaches all corners of 1 m × 1 m without binding +- [ ] Positional accuracy ≤ 2 mm over 500 mm travel (open-loop) +- [ ] Cuts a 100 mm square within 1 mm squareness +- [ ] No persistent electronics overheating after 30-minute continuous jog + +--- + +### 3.2 Phase 2: Full-Scale (4′ × 8′, 8-Belt Gordix Kinematics) + +**Goal:** A production-capable machine with constraint-locked yaw control, DC geared servos for torque and reliability, and a proper spindle for woodworking. + +**Target Budget:** ~$737 (excluding frame lumber) + +**Core Specs:** +- Work area: 4′ × 8′ (1.2 m × 2.4 m) or optionally 4′ × 4′ +- Kinematics: 8-belt Gordix style (twin lines to each of 4 corners → constraint-locked, no yaw) +- Motors: 4× Etom ET-WGM58AE 24 V DC geared servo + planetary gearbox + high-res encoder +- Drivers: Custom ESP32-S3 PCB v1.0 with 8× TMC2209 (UART, 2 buses) +- Sled: 6 mm milled aluminum baseplate (CNC-milled or waterjet) +- Spindle: Makita RT0701C (1.25 HP, variable speed 10,000–30,000 RPM) +- Belts: 2.0 mm Dyneema braided cord (zero-stretch, breaking strength 450 kg) +- Z-axis: Dual linear rails + SFU1204 ball screw + active NEMA 17 +- Frame: 2×4 lumber or 80/20 aluminum extrusion perimeter + +**Phase 2 Deliverables:** + +| # | Task | Est. Effort | Dependencies | +|---|------|-------------|-------------| +| P2.1 | Fabricate custom ESP32-S3 PCB (v1.0 layout in KiCad) | 5 days | PCB schematic (done), Phase 1 learnings | +| P2.2 | Populate and test PCB (solder, reflow, debug) | 2 days | P2.1 | +| P2.3 | Write and integrate 8-belt FluidNC custom kinematics module | 4 days | P2.2, kinematics.py from research | +| P2.4 | Build 4′×8′ perimeter frame | 2 days | Lumber/extrusion ordered | +| P2.5 | Fabricate aluminum sled (waterjet/CNC) | 3 days | Sled CAD model | +| P2.6 | Assemble DC gear servos + planetary gearboxes on spool brackets | 2 days | P2.4 | +| P2.7 | String and tension 8-belt Gordix configuration | 1 day | P2.5, P2.6 | +| P2.8 | Machine calibration routine (self-calibration via Maslow4-style spoofing) | 2 days | P2.3, P2.7 | +| P2.9 | Cut full-sheet test pattern (18 mm plywood, pocket + contour) | 1 day | P2.8 | +| P2.10 | Accuracy measurement and backlash compensation | 1 day | P2.9 | +| P2.11 | Gate review — proceed to Phase 3? | — | P2.10 | + +**Success Criteria (Phase 2):** +- [ ] All 8 belts tensioned; sled maintains orientation within ±0.5° across full workspace +- [ ] Positional accuracy ≤ 0.5 mm over 1 m (closed-loop compensation) +- [ ] Makita router produces clean edges in 18 mm plywood at 4 mm/s feed +- [ ] Self-calibration routine completes without manual intervention +- [ ] DC servos handle stall condition without damage (fault/pause) + +--- + +### 3.3 Phase 3: Production Refinement + +**Goal:** Polish the design into a reliable, reproducible, documented product — suitable for semi-professional use, kit sales, or open-source publication. + +**Phase 3 Deliverables:** + +| # | Task | Est. Effort | Dependencies | +|---|------|-------------|-------------| +| P3.1 | PCB v1.1 — fix any issues from v1.0; add ESD protection, fusing | 3 days | Phase 2 PCB testing | +| P3.2 | Design and fab enclosure (electronics box with fan/cooling) | 3 days | P3.1 | +| P3.3 | Dust boot for Makita RT0701C (3D-printable or vacuum-form) | 2 days | Phase 2 dust concept | +| P3.4 | Calibration software GUI (standalone web app or FluidNC plugin) | 5 days | Phase 2 calibration routine | +| P3.5 | Comprehensive documentation: build guide, wiring diagram, BOM links, CAM setup | 5 days | All prior phases | +| P3.6 | Safety features: e-stop circuit, belt guard, spindle interlock | 2 days | P3.1 | +| P3.7 | Long-duration reliability test (10-hour continuous cutting) | 2 days | P3.1–P3.6 | +| P3.8 | Release: tag v1.0, publish repo, create release assets | 1 day | P3.7 | + +**Success Criteria (Phase 3):** +- [ ] Electronics enclosure passes thermal test (ambient 25 °C, 4-hour run, no component >70 °C) +- [ ] Dust collection captures ≥90 % of chips at router zone +- [ ] Documentation covers full assembly from raw lumber to first cut +- [ ] 10-hour reliability test with zero mechanical failures +- [ ] Repo tagged v1.0 with release artifacts (PCB Gerbers, 3D-printable STLs, BOM CSV) + +--- + +## 4. Milestones & Dependencies + +```mermaid +gantt + title CNC Router Project Timeline + dateFormat YYYY-MM-DD + axisFormat %b %Y + + section Research (Done) + Competitive Analysis :done, 2026-06-01, 14d + Kinematics Simulation :done, 2026-06-05, 15d + PCB Schematic & Netlist :done, 2026-06-10, 10d + FluidNC Config YAML :done, 2026-06-15, 5d + + section Phase 1 — Prototype + Order Parts :p1-1, after research, 2d + 3D Print Sled & Anchors :p1-2, after p1-1, 5d + Build Frame 1m×1m :p1-3, after p1-2, 2d + Assemble Electronics :p1-4, after p1-1, 3d + Flash FluidNC + 4-Belt Kine :p1-5, after p1-4, 2d + Calibrate & Test :p1-6, after p1-5, 5d + Phase 1 Gate Review :milestone, after p1-6, 0d + + section Phase 2 — Full-Scale + PCB Layout in KiCad :p2-1, after p1-6, 7d + PCB Fab & Populate :p2-2, after p2-1, 5d + Write 8-Belt FluidNC Module :p2-3, after p2-2, 5d + Build 4′×8′ Frame :p2-4, after p2-2, 3d + Fab Aluminum Sled :p2-5, after p2-2, 5d + Assemble DC Servo Drives :p2-6, after p2-4, 3d + String 8-Belt Kinematics :p2-7, after p2-5 p2-6, 2d + Calibrate & Test Cuts :p2-8, after p2-7, 5d + Phase 2 Gate Review :milestone, after p2-8, 0d + + section Phase 3 — Production + PCB v1.1 Revisions :p3-1, after p2-8, 5d + Enclosure & Dust Boot :p3-2, after p3-1, 5d + Calibration GUI :p3-3, after p2-8, 7d + Documentation & Safety :p3-4, after p3-2, 7d + Reliability Test :p3-5, after p3-4, 3d + v1.0 Release :milestone, after p3-5, 0d +``` + +**Critical Path:** Order → Print/Build → Electronics → Firmware → Calibrate → Test + +**Key dependency chain:** +1. PCB schematic (done) → KiCad layout (Phase 2) → PCB fab → firmware integration +2. Kinematics simulation (done) → FluidNC custom kinematics module (Phase 2) → calibration +3. Prototype tests (Phase 1) → inform full-scale design decisions (Phase 2) +4. Phase 1 Gate Review → Investment in Phase 2 materials +5. Phase 2 Gate Review → Production refinement investment + +--- + +## 5. Risk Register + +| # | Risk | Likelihood | Impact | Mitigation | +|---|------|-----------|--------|------------| +| R1 | **Belt stretch / creep over 4 m span** | Medium | High | Use Dyneema braided cord (zero-stretch) for production; GT2 timing belts only for prototype. Monitor tension with load cells in Phase 3. | +| R2 | **Yaw control insufficient in 4-belt prototype** | High | Medium | Accept software-based yaw correction for Phase 1. The whole point of Phase 1 is to measure how bad yaw is before building 8-belt. If yaw is unacceptable → skip straight to 8-belt prototype. | +| R3 | **TMC2209 current insufficient for NEMA 23 / DC servo replacement** | Low | Medium | TMC2209 handles 2.8 A peak — fine for NEMA 17. If NEMA 23 needed, switch to TMC5160 (external FETs, up to 20 A). PCB v1.0 pinout compatible with both. | +| R4 | **Firmware complexity — custom FluidNC kinematics module** | Medium | High | Starting from Maslow4's existing FluidNC fork. The Maslow4 firmware already implements a 4-belt kinematic transform; our work is adapting it for 8-belt Gordix geometry, not writing from scratch. | +| R5 | **Dust management — router chips affecting belt/sled mechanics** | Medium | Medium | Active vacuum nozzle in Phase 3; sealed bearings on spools; belt path kept below sled plane where possible. Prototype tests will reveal how bad chip accumulation is. | +| R6 | **PCB v1.0 has layout/routing errors** | Medium | Medium | Redesign for v1.1 is budgeted in Phase 3. Produce only 3–5 boards for v1.0; test thoroughly before committing to volume. | +| R7 | **Gordix-style 8-belt geometry has unreachable zones** | Low | High | Kinematics simulation shows full workspace coverage for 1.2 m × 2.4 m with the current anchor offsets. If zones are problematic, adjust anchor positions or accept reduced workspace. | +| R8 | **DC geared servo control via TMC2209 inadequate (no closed-loop position)** | Medium | High | TMC2209 is open-loop step/dir. For Phase 2, we pair TMC2209 with external encoder feedback via ESP32-S3 PCNT (pulse counter) for software-based closed-loop. If this proves unreliable, switch to TMC5160+encoder or dedicated servo drives. | +| R9 | **Cost overrun — BOM estimate out of date** | Medium | Low | All BOM prices verified June 2026 from current AliExpress/Amazon pricing. Buffer of 15% already included in estimates. | +| R10 | **Self-calibration routine fails on asymmetrical belt stretch** | Low | Medium | Develop manual calibration fallback (measure 4 corner distances, input via web UI). Maslow4's calibration algorithm is well-documented and can be adapted. | + +--- + +## 6. Testing Strategy + +### 6.1 Phase 1 Tests + +| Test | Method | Pass Criteria | +|------|--------|--------------| +| **Belt tension uniformity** | Measure belt sag at 4 corners with force gauge | All 4 belts within ±10 % tension | +| **Workspace coverage** | Jog sled to 9 grid points; record if reachable | 9/9 points reachable | +| **Squareness** | Cut 100 mm square, measure diagonals | Diag difference ≤ 2 mm | +| **Positional accuracy** | Cut grid at 5 positions, measure with calipers | X/Y error ≤ 2 mm over 500 mm | +| **Repeatability** | Return-to-center test ×10 | ±0.5 mm | +| **Electronics thermal** | IR thermometer after 30-min continuous jog | TMC2209 ≤ 70 °C, ESP32 ≤ 60 °C | +| **Z-axis plunge test** | Plunge 3 mm into pine at 5 mm/s | Clean cut, no Z-binding | + +### 6.2 Phase 2 Tests + +| Test | Method | Pass Criteria | +|------|--------|--------------| +| **8-belt yaw constraint** | Measure sled rotation with dial indicator during XY move | ≤ 0.5° rotation across full span | +| **DC servo torque test** | Feed rate ramp until stall | ≥ 8 mm/s in 18 mm plywood | +| **Closed-loop accuracy** | Cut 500 mm line, measure with laser distance meter | ≤ 0.5 mm error | +| **Calibration routine** | Run auto-calibration 3 times, compare results | ±0.3 mm agreement | +| **Dust test** | Cut 1 m pocket in MDF with/without dust boot | Chips in workspace ≤ 10 g | +| **Makita RT0701C** | Test all speed settings, 10 min continuous | No overheating, smooth cut | +| **Limit switch test** | Trigger each limit 10× | 100 % reliable stop | + +### 6.3 Phase 3 Tests + +| Test | Method | Pass Criteria | +|------|--------|--------------| +| **Thermal chamber** | 4-hour cut cycle at 25 °C ambient | Max component temp ≤ 70 °C | +| **Long-duration reliability** | 10-hour continuous cutting (interleaved patterns) | Zero mechanical failures | +| **Safety system** | E-stop + belt guard test | < 100 ms stop time | +| **Documentation walkthrough** | Independent builder follows build guide | Complete assembly in ≤ 20 hours | + +--- + +## 7. Next Actions (DO NOW) + +These are the 5 concrete steps to execute immediately: + +### 7.1 Order Prototype Parts + +**Source the full Phase 1 BOM** from BOM-Evaluation.md ($261 total). Priority items: +- [ ] 4× NEMA 17 steppers ($56) +- [ ] 4× TMC2209 drivers ($28) +- [ ] ESP32 NodeMCU dev board ($6) +- [ ] GRBL CNC Shield or protoboard ($10) +- [ ] 2× GT2 6 mm timing belts, 10 m rolls ($24) +- [ ] 24 V 10 A PSU ($28) +- [ ] Bosch Colt / Makita clone spindle ($45) +- [ ] Mini linear slide Z-axis ($35) +- [ ] Fasteners, bearings, hardware ($15) +- [ ] 3D printer filament (PLA/PETG) for sled + anchors (~$6) + +### 7.2 Design Sled & Anchor 3D-Printable STLs + +Create CAD models (Fusion 360 / Onshape) for: +- **Sled body:** PLA/PETG with dual-mount holes per corner (compatible with 8-belt upgrade) +- **Corner anchors:** With manual clamp handles for quick frame attachment +- **GT2 spool holders:** Captive bearing mounts for smooth belt travel +- **Z-axis bracket:** Mount for mini linear slide + spindle clamp +- Export STLs for printing + +### 7.3 KiCad PCB Layout (Start in Parallel) + +Convert the completed schematic netlist into KiCad: +- [ ] Import ESP32-S3-WROOM-1 footprint +- [ ] Place 8× TMC2209 (QFN-24 package) with decoupling caps +- [ ] Route 4-layer stackup (signal/GND/power/signal) +- [ ] UART1 bus to 4 drivers, UART2 bus to 4 drivers +- [ ] JST XH connectors for motor outputs +- [ ] 24 V input with TVS diode + 5 A fuse +- [ ] MP9942 buck reg + AMS1117-3.3 LDO +- [ ] Limit switch / probe headers +- [ ] Spindle PWM + direction header +- [ ] Run ERC/DRC; order 5 prototype boards from JLCPCB + +### 7.4 Write FluidNC Custom Kinematics Module + +Starting from the Maslow4 FluidNC fork: +- [ ] Clone `github.com/MaslowCNC/Maslow_4` firmware repo +- [ ] Locate `kinematics/` directory in FluidNC source +- [ ] Implement 4-belt kinematic transform (forward + inverse) in C++ +- [ ] Implement 8-belt Gordix kinematic transform +- [ ] Create a custom machine config YAML for each phase +- [ ] Add workspace boundary checking +- [ ] Build and flash to ESP32 dev board +- [ ] Test with serial G-code sender (bCNC or Candle) + +### 7.5 Set Up Cutting Area & Safety + +- [ ] Allocate 2 m × 2 m clear floor/bench space +- [ ] Build 1 m × 1 m plywood frame as first structural task +- [ ] Prepare dust extraction (shop vac + cyclone) +- [ ] Set up workbench for electronics assembly (soldering station, multimeter, scope) +- [ ] Install hearing protection / dust mask / fire extinguisher in workspace + +--- + +## Appendix A: Software Pipeline + +``` +CAD (Fusion 360 / Onshape / Inkscape) + │ + ▼ +CAM (Kiri:Moto / Estlcam / OpenBuilds CAM) + │ Generates standard G-code (.nc or .gcode) + ▼ +G-code Sender (bCNC / Candle / Web Interface) + │ Streams over USB or Wi-Fi + ▼ +FluidNC (ESP32-S3) + │ Custom kinematics module: + │ 4-belt: forward(Kartesian X,Y → 4 belt lengths) + │ 8-belt: forward(Kartesian X,Y → 8 belt lengths) + │ Inverse: belt lengths → X,Y via least-squares (scipy) + ▼ +TMC2209 Stepper Drivers (UART mode) + │ + ▼ +NEMA 17 / DC Geared Servo Motors + │ + ▼ +Belt Spools → Sled → Cutter +``` + +## Appendix B: Key Reference Links + +| Resource | URL | +|----------|-----| +| Maslow 4 firmware | github.com/MaslowCNC/Maslow_4 | +| Maslow 4 boards | github.com/MaslowCNC/Boards | +| Maslow 4 electronics | github.com/MaslowCNC/Electronics | +| Maslow 4 PCB (OSHW Labs) | oshwlab.com/BarbourSmith/maslow4 | +| FluidNC wiki | wiki.fluidnc.com | +| FluidNC config docs | wiki.fluidnc.com/en/config/ | +| FluidNC kinematics docs | wiki.fluidnc.com/en/config/kinematics | +| TMC2209 datasheet | trinamic.com/products/integrated-circuits/tmc2209/ | +| ESP32-S3 datasheet | espressif.com/en/products/socs/esp32-s3 | +| Gordix info | gordix.com | +| Cubiio X | cubiio.com | + +--- + +> **Next milestone:** Parts ordered + first sled STL printed. Estimated: 7 days from now. +> **This document should be updated after each phase gate review. \ No newline at end of file